Elongated fuel-air bypass for internal conbustion engine

ABSTRACT

An elongated fuel-air bypass is connected between an outlet port of a fuel-air mixing device and an inlet port of an intake manifold of an internal combustion engine. The elongated bypass apparatus includes an elongated bypass conduit formed of a thermally conductive material and which has sufficient length, exterior surface area and thermal conductivity to enable it to cause liquid fuel introduced through the fuel-air mixing device to change from a liquid state to a gaseous state prior entry into the one or more cylinders of the internal combustion engine. Turbulence creating mechanisms, such as venturis or baffles, are provided in the elongated bypass conduit for creating turbulence in the fuel-air mixture flowing therethrough. An after-air supply tube is provided to supply after-air near an upstream end of the fuel-air bypass conduit, and is controlled by an after-air valve to provide for a lean fuel-air mixture. Also provided is a liquid additive system for supplying water and/or alcohol into the fuel-air bypass conduit. A start-up fuel injection system is provided to inject a burst of fuel into the fuel-air bypass conduit at initial start-up of the internal combustion engine. At least one reparticulation reservoir is provided in the bottom of a portion of the fuel-air bypass conduit in order to enable quick start-up of the engine after flooding.

This is a continuation application of Ser. No. 08/541,097, filed Oct.11, 1995 U.S, Pat. No. 5,606,956.

BACKGROUND OF THE INVENTION

The invention relates generally to improvements in internal combustionengines and, more particularly, to an elongated fuel-air bypass devicefor use between a fuel-air mixing device and an intake manifold of aninternal combustion engine.

Although many improvements have been proposed over the years for thebasic internal combustion engine, it has remained the case that the fuel(e.g. gasoline) supplied into the cylinder or cylinders of the internalcombustion engine has been a wet saturated fuel. That is, in carburetorengines and throttle body fuel injector engines, liquid fuel is drawn orpumped into an air stream in the throat of the fuel-air mixing device,in order create a fuel-air mixture. This fuel-air mixture is feddirectly into the intake manifold and, in turn, into the individualcylinders of the internal combustion engine. In a multi-port fuelinjection engine, the liquid fuel is sprayed into the cylinders in anatomized form by the fuel injectors. In any event, the fuel-air mixtureentering the cylinders in prior art internal combustion engines has beena mixture of air and wet saturated fuel.

Although the multi-port fuel injection system is an improvement over thecarburetor system and has been shown to be approximately 6% moreefficient, this increase in efficiency is attained due to a bettercontrol of the fuel-to-air ratio. That is, there is no real improvementin the actual combustion of the fuel, but only in the monitoring of thefuel-air ratio under different load conditions, such as during coastingor deceleration.

Wet saturated fuel does not burn. Rather, the wet saturated fuel must beprepared for burning by being vaporized (or gasified). In the prior artinternal combustion engines, this vaporization of the fuel has occurredin the cylinder due to the heat of compression and combustion.

Therefore, because the fuel must change state from liquid to gas priorto it being combusted in the cylinder, complete combustion of the fuelis not possible. Therefore, improvements in the efficiency of internalcombustion engines to date have been severely limited.

Engine efficiency has also been disadvantageously affected in today'sautomobiles because of the federal laws preventing the use of leadedgasoline. That is, engines with higher compression ratios will tend tocause preignition or "knocking." This knocking was, however, eliminatedby use of tetryl ethyl lead in gasoline (i.e., leaded gasoline). Thelead in the gasoline was used to slow the burning of the gasoline andthus slow the movement of the flame front, thereby preventing knocking.When leaded gasolines were outlawed, it became necessary to reduce thecompression ratios of new engines in order to prevent the engines fromknocking when using the unleaded gasoline. The use of lower compressionratios results in a decreased engine performance and efficiency.

Air pollution due to hydrocarbon and carbon monoxide emissions ofinternal combustion engines is becoming an increasing concern,especially in metropolitan areas. The major attempts thus far to reduceemissions have been by using lean burn engines and by providingair-cleaning devices, such as the catalytic convertor, downstream of theengine. Although these innovations have proven somewhat successful, theability to reduce emissions in this manner is limited.

Another problem in prior art internal combustion engines is that ofengine flooding, wherein a surplus of liquid fuel becomes present in theengine due to the continual infeed of liquid fuel prior to initialignition of the fuel.

Various attempts have been made to improve the performance andefficiency of internal combustion engines, but such attempts have beeneither impractical, or only mildly successful. In U.S. Pat. No.4,478,198, a fuel treating apparatus is disclosed whereby adual-compartment insert unit is interposed between the carburetor andthe intake manifold of an internal combustion engine, and an elongatedconduit is attached between an outlet port of the upstream compartmentand an inlet port of the downstream compartment. A heat exchanger andbaffle arrangement is provided to heat and cause mixing of the fuel-airmixture traveling through the conduit. However, the fuel treatingapparatus of this U.S. patent endeavors only to improve atomization ofthe fuel-air mixture and, accordingly, the conduit is of a relativelysmall diameter and cannot accommodate all of the fuel-air flow outputfrom the carburetor. Therefore, a valved bypass opening must be providedbetween the upstream and downstream compartments to allow for directfuel-air flow from the carburetor to the intake manifold. Thisarrangement is thus beset by the same disadvantage as discussed above.In particular, this arrangement continues the prior art concept offeeding a mixture of air and wet saturated fuel into the cylinders ofthe internal combustion engine. Therefore, it remains necessary for thefuel entering the cylinders to be prepared for burning by being gasifiedin the cylinders by heat of compression and combustion. In addition,this arrangement is beset by the problem that, if the fuel-air mixtureis not allowed to readily flow through the bypass so as to pass directlyfrom the carburetor to the intake manifold, the small diameter of theconduit will effectively starve the engine of the needed fuel-airmixture.

U.S. Pat. No. 4,200,070 is directed to a fuel-air mixture control forsupercharged internal combustion engines. In this patent, a superchargeris interposed between an induction conduit leading from the carburetorand an induction conduit leading to the intake manifold. A straightvertical bypass tube bypasses the supercharger so that the fuel-airmixture will pass directly from the carburetor to the intake manifoldduring idling, and such straight vertical tube is provided directlyabove a heat transfer plate which is heated by exhaust gases. With thisarrangement, any precipitated liquid fuel will drop through the straightvertical tube and onto the heat transfer plate to be vaporized. However,this invention also is beset by the same problem as discussed above.That is, the fuel-air mixture introduced into the intake manifold andthe cylinders from the carburetor is a mixture of air and wet saturatedfuel. Therefore, as with the other prior art, the liquid fuel must beprepared in the cylinder by being vaporized therein due to heat ofcompression and combustion, thereby reducing the performance andefficiency of the engine.

Other attempts for improving the performance and/or efficiency ofinternal combustion engines are disclosed in U.S. Pat. Nos. 5,046,475,4,355,623, 4,770,151, 4,300,513, 4,286,564, 4,137,875 and 5,040,518.However, these attempts have not presented solutions adequate toovercome the above-described disadvantages of the prior art.

SUMMARY OF THE INVENTION

An object of the present invention is to overcome the above-describeddisadvantages inherent in the prior art.

A particular object of the present invention is to considerably improvethe performance and efficiency of an internal combustion engine bycausing the fuel-air mixture delivered into the cylinders of theinternal combustion engine to be in gaseous form rather than in a wetsaturated form.

A further object of the invention is to reduce air pollution by reducingcarbon monoxide and hydrocarbon emissions from an internal combustionengine.

Another object of the invention is to enable the use of internalcombustion engines having higher compression ratios than can currentlybe used with unleaded gasoline, by providing an arrangement which allowsthe addition of water and/or alcohol into the fuel-air mixture to beburned in the cylinders.

A still further object of the present invention is to facilitate quickstarting of an internal combustion engine after it has been flooded, byproviding at least one reparticulation reservoir in a fuel-air bypassconduit according to the present invention.

Yet another object of the present invention is the provision of abackfire safety device which will allow for the absorption of highpressures created by backfiring.

An additional object of the present invention is to create a leanfuel-air mixture by supplying after-air into the bypass conduit.

The above and other objects and advantages are attained according to thepresent invention by the use of a fuel-air bypass apparatus in aninternal combustion engine, wherein the bypass apparatus comprises anelongated bypass conduit operably coupled between the outlet port of afuel-air mixing device and the inlet port of an intake manifold forpassing a fuel-air mixture from the fuel-air mixing device to the intakemanifold, turbulence creating means for creating turbulence in thefuel-air mixture flowing through the elongated bypass conduit, whereinthe elongated bypass conduit is formed of a thermally conductivematerial, and wherein the elongated bypass conduit has a length, anexterior surface area and a thermal conductivity sufficiently great soas to constitute a means for causing liquid fuel introduced through thefuel-air mixing device to change from a liquid state to a gaseous stateprior to entry into the at least one cylinder.

In a preferred form of the invention, the elongated bypass conduit isformed of copper to provide for great thermal conductivity. Theturbulence creating means can be formed by a plurality of venturisprovided in the elongated bypass conduit successively along the lengththereof, or by a plurality of baffles provided in the elongated bypassconduit successively along the length thereof.

The minimum cross-sectional area of the elongated bypass conduit shouldbe at least as great as the minimum cross-sectional area of the throatof the fuel-air mixing device. The elongated bypass conduit can becircular or rectangular in cross-section, or can have any other suitablecross-sectional shape.

The apparatus further includes a liquid additive system for supplying atleast one liquid additive into the fuel-air bypass conduit to mix withthe fuel-air mixture flowing therethrough. The liquid to be mixed withthe fuel-air mixture can be water, alcohol or water and alcohol.

The apparatus further includes a start-up fuel injection system forinjecting a burst of fuel into the fuel-air bypass conduit at initialstart-up of the internal combustion engine. Also, at least onereparticulation reservoir is provided in a bottom of a portion of thefuel-air bypass conduit, in order to enable quick starting of the engineafter flooding thereof.

The fuel-air bypass apparatus also includes a backfire safety deviceincluding a backfire safety port formed in the fuel-air bypass conduit,a safety port cover hinged to the fuel-air bypass conduit to cover thebackfire safety port, and a biasing spring biasing the safety port covertoward a closed condition over the backfire safety port. A pressuredischarge absorbing canister is connected to the backfire safety port bya pressure discharge pipe.

The fuel-air bypass conduit of the present invention can be formed as asingle piece conduit, or can be formed of a plurality of conduitsections longitudinally successively secured together.

The bypass conduit can also be configured in many different ways, forexample, in a coil-shape or in a zig-zag shape, so long as theconfiguration enables the bypass conduit to be installed in a desiredenvironment and allows the conduit to be heated, preferably with heatfrom the internal combustion engine.

Additional objects and advantages of the present invention will berecognized upon a reading of the following detailed description of theinvention with reference to the accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a front elevation view of an embodiment of the fuel-airbypass of the present invention;

FIG. 2 shows a plan view of the embodiment of FIG. 1;

FIG. 3 shows an exploded perspective view of a connecting saddle forconnecting a fuel-air bypass of FIG. 1 to an internal combustion engine;

FIG. 4 shows a venturi section of the fuel-air bypass;

FIG. 5 shows a front elevation view of a second embodiment of thefuel-air bypass of the present invention;

FIG. 6 shows a cross-sectional view of a connection saddle used in thesecond embodiment of the present invention;

FIG. 7 shows a fuel-air bypass according to a third embodiment of thepresent invention;

FIG. 8 shows a partial cross-sectional view of a heat exchanger used inthe third embodiment of the present invention;

FIG. 9 shows a baffle arrangement for use in the third embodiment of thepresent invention;

FIG. 10 shows a schematic elevation view of an internal combustionengine having a fuel-air bypass arrangement according to the presentinvention;

FIGS. 11-11F show elevation views of various individual sections whichcan be used to make up the fuel-air bypass conduit of the presentinvention;

FIG. 11G shows an end view of an end flange used to connect the varioussections of the fuel-air bypass;

FIG. 12A shows an explanatory sectional view of a section of thefuel-air bypass having baffles;

FIG. 12B shows an end view of the bypass section shown in FIG. 12A;

FIG. 13 shows a partially exploded sectional view of a venturi sectionof a fuel-air bypass connected to a fuel-air mixing device;

FIG. 14 shows a partially exploded sectional view showing a section ofthe bypass having baffles and being connected to a fuel-air mixingdevice;

FIG. 15 shows an alternative form of venturi for use in the fuel-airbypass of the present invention;

FIG. 16 shows yet another alternative form of venturi for use in thefuel-air bypass of the present invention;

FIG. 17 shows a side elevation view of a backfire safety device for usewith the fuel-air bypass of the present invention;

FIG. 18 shows a front elevation view of a portion of the backfire safetydevice shown in FIG. 17;

FIG. 19 shows a schematic view of a liquid additive induction system andan after-air control system for use with the fuel-air bypass of thepresent invention;

FIG. 20 shows one embodiment of an after-air control system which can beused in the arrangement shown in FIG. 19;

FIG. 21 shows another embodiment of the after-air control system whichcan be used in the arrangement shown in FIG. 19;

FIG. 22 shows a schematic view of a fuel injection arrangement for usein the fuel-air bypass of the present invention;

FIG. 23 shows a partially sectional view of a portion of the fuel-airbypass having a reparticulation reservoir;

FIG. 24 shows one embodiment of a mounting arrangement for the fuel-airbypass of the present invention;

FIG. 25 shows another embodiment of a mounting arrangement for thefuel-air bypass of the present invention;

FIG. 26 shows a fuel-air bypass arrangement according to the presentinvention installed in an automobile;

FIGS. 27 and 28 show particular arrangements of fuel-air bypassesaccording to the present invention; and

FIGS. 29A-29C schematically depict three alternative configurations forthe fuel-air bypass conduit according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Various embodiments and features of the fuel-air bypass arrangementaccording to the present invention will now be described in detail withreference to the drawings. It is to be noted that various embodiments ofthe overall arrangement of the fuel-air bypass of the present inventionare shown and described, and also that various embodiments of individualfeatures of the fuel-air bypass arrangement of the present invention areshown and described. It is contemplated that the various alternativeembodiments of the individual features can be used in variouscombinations including combinations not particularly described andshown. In addition, it is to be noted that the present inventionencompasses both a fuel-air bypass device in combination with aninternal combustion engine, and the fuel-air bypass device itself in itsvarious forms. It is further contemplated that the fuel-air bypassdevice of the present invention will be useful as original equipment inautomobiles, as well as in the form of retrofit kits for improving aninternal combustion engine subsequent to original manufacturer. Thepresent invention also contemplates a method of operating the fuel-airbypass device.

A first detailed embodiment of the fuel-air bypass device, generallyindicated at 10, and its particular mounting system for mounting to aninternal combustion engine will now be described with reference to FIGS.1-4.

In this embodiment, a fuel-air bypass conduit 100 is mounted between anoutlet of a fuel-air mixing device 11 (for example, a carburetor or athrottle body fuel injector) and an inlet of an intake manifold 12 of aninternal combustion engine. Reference numeral 36 refers to an aircleaner. The fuel-air bypass conduit 100 is mounted between the fuel-airmixing device 11 and the intake manifold 12 by a connector saddle showngenerally by reference numeral 3 and depicted in more detail in FIG. 3.

In particular, the connector saddle 3 includes a first chamber housing13 having a first housing top flange 14, a first housing bottom flange15 and a first housing sidewall 16 interconnected between the firsthousing top flange 14 and the first housing bottom flange 15. The firsthousing top flange 14 is secured to the fuel-air mixing device 11 by anysuitable means, such as bolts or the like. The connector saddle 3 alsoincludes a second chamber housing 17 which includes a second chamberhousing top flange 18, a second chamber housing bottom flange 19 and asecond chamber housing sidewall connecting between the second chamberhousing top flange 18 and the second chamber housing bottom flange 19.The second chamber housing bottom flange 19 is secured to the intakemanifold 12 by any suitable means, such as bolts or the like. Animpermeable block-off plate 21 is interposed between the first housingbottom flange 15 and the second housing top flange 18 in order toprevent flow of the fuel-air mixture between the first chamber 13 andthe second chamber 17.

The connector saddle 3 also includes a first tube 22 extending radiallyoutwardly from the first chamber 13, and a second tube 24 extendingradially outwardly from the second chamber 17. A central conduit 23extends between the outlet tube 22 and the inlet tube 24, therebycompleting the bypass conduit 100 fluidically connected between theoutlet of the fuel-air mixing device 11 and the inlet of the intakemanifold 12.

As seen best in FIG. 2, the bypass conduit 100 includes a plurality ofventuris 25 which constitute turbulence creating means. It will beunderstood that some or all of the venturis 25 can be replaced by otherturbulence creating means, such as various baffle configurations orvarious other conduit deformations, as will be described in more detaillater. The venturis, or other turbulence creating means, are necessaryfor breaking up the boundary layer of the fuel-air flow and therebyensuring proper mixing of the fuel-air mixture.

The connector saddle 3 can be formed of any material which can withstandthe normal running conditions of an internal combustion engine, butwould preferably be formed of metal, such as steel or copper. Theconduit 100 is formed of a metal having a high thermal conductivity soas to provide good heat conduction from the ambient environment in theengine compartment to the fuel-air mixture flowing through the conduit100. Accordingly, although a steel conduit has proven somewhat effectiveunder certain conditions, forming the conduit 100 of copper has provenfar superior due to the fact that the thermal conductivity of copper isapproximately 10 times greater than the thermal conductivity of steel.In particular, copper has a thermal conductivity of 224 Btu/h×ft×°F,whereas a mild steel has a thermal conductivity of 26 Btu/h×ft×°F.Another critical feature of the present invention is the length,cross-sectional area and exterior surface area of the fuel-air bypassconduit. In particular, the elongated bypass conduit 100 must have alength, an exterior surface area and a thermal conductivity sufficientlygreat so as to constitute a means for causing liquid fuel introducedthrough the fuel-air mixing device to change from a liquid state to agaseous state prior to entry into the cylinders of the internalcombustion engine. It is also important that the minimum cross-sectionalarea of the conduit 100 (e.g. the cross-sectional area at the venturis25) is at least as large as a minimum cross-sectional area of the flowpassage of the fuel-air mixing device 11, in order to ensure the leastpossible resistance to flow of the fuel-air mixture through the conduit100. Specific examples of conduit configurations used with particularinternal combustion engines will be described below.

After-air is preferably added into the fuel-air bypass conduit 100downstream of the fuel-air mixing device 11 through the after-air supplytube 26. An after-air valve 26a is provided for controlling theafter-air quantity. The after-air valve 26a can be any suitable valve,such as a slide valve or a rotary valve. Details of after-air controlwill be set forth below.

A second embodiment of the invention, described with reference to FIGS.5 and 6, utilizes a modified connector saddle 3a. This connector saddle3a includes a top flange 14a which is secured to the outlet of thefuel-air mixing device 11, and a bottom flange 15a which is secured tothe inlet of the intake manifold 12. A sidewall 16a connects between thetop flange 14a and the bottom flange 15a. Inside the modified connectorsaddle 3a is provided a separation plate 27 spanning the inner space ofthe saddle in an inclined manner so as to form on opposing sides thereofa first chamber 28 and a second chamber 29. As with the connector saddle3, extending chamber 28 has an outlet tube 22a extending radiallyoutwardly therefrom, and the second chamber 29 has an inlet tube 24extending radially inwardly thereto.

The use of either the connector saddle 3 or the modified connectorsaddle 3a is advantageous in that it allows the fuel-air mixing device11 to remain directly above the intake manifold 12, and is thusespecially adapted for use in a retrofit kit. However, the fuel-airbypass device of the present invention can operate equally well withother means of mounting between the fuel-air mixing device 11 and theintake manifold 12 so long as the mounting means does not createresistance to flow of the fuel-air mixture into and out of the fuel-airconduit 100. For example, in embodiments to be described later, afuel-air conduit 200 will be described as being connected directly tothe fuel-air mixing device 11 and the intake manifold 12 simply by theuse of suitable flanges which allow the conduit 200 to be bolted orotherwise suitably fastened to the outlet of the fuel-air mixing device11 and the inlet of the intake manifold 12.

Although the fuel-air conduit of the present invention is to be formedof a highly thermally conductive material, such as copper, and is tohave a length and surface area sufficient to cause the liquid fuel to begasified prior to entry into the cylinders and, preferably, prior toentry into the intake manifold 12, it is also possible to provide a heatexchanger 33 (see FIGS. 7 and 8) for enhancing the heating effect. Inthis regard, it is contemplated that the housing of heat exchanger 33surrounds the conduit 100 and has a fluid inlet 35 for flow of fluidinto a fluid reservoir 88, and a fluid outlet 34 for flow of the fluidout of the reservoir 88. The fluid used in the heat exchanger 33 can beany suitable heated fluid, such as the engine coolant or engine exhaustgases. This heat exchanger 33 is especially useful in eliminating arefrigerant effect which may occur at start-up in very cold climates.However, it is contemplated that, when the conduit 100 is formed ofcopper, such heat exchanger may be unnecessary as little or norefrigerant effect will take place.

As shown in FIGS. 7 and 9, an alternative to one or more of the venturis25 is one or more helical baffle plates 31 concentrically orientedwithin a baffle chamber 30 about an axis 32. Such baffles will also actas turbulence creating means.

FIG. 10 schematically depicts a further embodiment of the presentinvention, wherein a fuel-air bypass conduit 200 is directly connectedbetween a fuel-air mixing device 11 and an intake manifold 12. Also inFIG. 10 are schematically depicted the after-air supply tube 26,venturis 251, a liquid additive supply line 141, a temperature sensor136, a fuel-air mixture sensor 137, a fuel injector 150, an ON/OFF typetemperature sensor 152 for use with the fuel injector, a reparticulationreservoir 160 and a backfire safety device 110. Each of these featuresof the invention will be described in detail below.

Next, although the fuel-air bypass conduit 100 or 200 can be formed asone continuous conduit, it is also contemplated that the bypass conduitcan be formed of a number of interconnected smaller sections. Examplesof these smaller sections are depicted in FIGS. 11A-11G. A straightconduit section 200a is shown in FIG. 11A with two end flanges 200bwhich can be connected to end flanges 200b of other conduit sections bybolts or other suitable fastening means. A gasket 200c to be interposedbetween the end flanges 200b of adjacent conduit sections is shown inFIG. 11B. Of course, however, any other suitable gasket or sealing meanscan be utilized. FIG. 11C shows a venturi section 200d, FIG. 11D showsan elbow section 200e, FIG. 11E shows a U-shaped section 200f, and FIG.11F shows a wedge section 200h. FIG. 11G shows an end view of one of theend flanges 200b, and depicts the end flange 200b as having bolt holes200g formed therein. Any number of various conduit configurations can beformed with the conduit sections shown in FIGS. 11A-11G. The preciseconfiguration of the conduit 200 is itself of little importance, exceptto the extent that configurations having the least resistance to fluidflow are preferred.

As an alternative to one or more of the venturis 25, 251, FIGS. 12A and12B show a conduit 100 having radially inwardly protruding baffles 231which, like the venturi, are effective to break up the boundary flowalong the inner wall of the conduit, thereby creating turbulence andimproving the mixing of the fuel-air mixture.

FIGS. 13 and 14 show the characteristic of the present invention thatthe minimum cross-sectional area of the conduit is at least as large asthe minimum cross-sectional area of the flow passage of the fuel-airmixing device 11. The minimum cross-sectional area of the flow passageof the fuel-air mixing device 11 is depicted in FIGS. 13 and 14 bydashed lines. As clear from FIG. 13, the minimum cross-sectional area ofthe throat of the fuel-air mixing device 11 is smaller than the throatof the venturi 251 of a conduit section 200d'. Similarly, FIG. 14clearly shows that the throat of the fuel-air mixing device 11 issmaller in cross-sectional area than the passage between the baffles 231provided in the conduit 200.

FIG. 14 illustrates a few details of a common fuel-air mixing device. Inparticular, the fuel-air mixing device includes a throttle 11b, an idleset screw 11c, an air screw 11d, an idling jet 11e, a fuel reservoir11f, and an air intake 11g. Upon retrofitting of an internal combustionengine having this configuration with the fuel-air bypass of the presentinvention, it has been found necessary to back out the idle set screw11c and the air screw 11d, because the interposition of the conduit 200results in such an increase in the combustion efficiency of the fuel inthe cylinders that the idle increases greatly and therefore must bereduced by throttle adjustment and increasing idle air flow (making theair-fuel mixture leaner).

FIG. 15 schematically depicts the air flow through the venturi section200d', and also shows an exploded view of the interconnection betweentwo conduit sections. The end flanges 200b are shown as having fastenerholes 200g therethrough for interconnection by bolts or the like. Analternative style venturi section 200d" is shown in FIG. 16. Thisbulbous-shaped venturi also acts as a turbulence creating means for thefuel-air mixture flow.

FIGS. 17 and 18 show a backfire safety device 110 connected to thefuel-air bypass conduit 200. The backfire safety device 110 includes abackfire port 111 which, as shown in FIG. 18, is preferably an elongatedopening formed in the conduit 200, and a backfire port cover 112pivotally connected to the conduit 200 by a backfire port cover hinge113. A backfire port closure spring 114 is provided to bias the backfireport cover 112 into a closed state, and a cover gasket 115 is providedto seal the backfire port 111 when the port cover 112 is in the closedstate. The backfire port 111 is connected to a pressure dischargeabsorbing canister 117 by a pressure discharge pipe 116. Preferably, thepressure discharge absorbing canister 117 will have a pressure absorbingmedium disposed therein. With this backfire safety device 110, upon theoccurrence of a pressure increase in the conduit 200 sufficient toovercome the biasing force of the closure spring 114, the backfire portcover 112 will be forced open to allow a pressure release into thepressure discharge pipe 116 to be absorbed in the pressure dischargeabsorbing canister 117.

FIG. 19 schematically illustrates a liquid additive and after-airinduction system for adding liquid additives, such as water and/oralcohol (ethanol), and after-air into the fuel-air mixture flowingthrough the conduit 200. First in this regard, it must be noted that theoperation of the pistons in the cylinders of the internal combustionengine will create a vacuum in the bypass conduit 200, and that thisvacuum is sufficient to draw liquid and after-air into the conduit 200from their respective supply lines 141, 26. The liquid additive andafter-air induction system 140 includes an after-air supply source 133,an after-air supply tube 26 leading from the after-air supply 133 to theconduit 200, and an after-air control valve 26a for controlling theamount of after-air flowing into the conduit 200. The after-air supplysource 133 can be any suitable air supply source, but should preferablyflow through an air cleaner, for example, the air cleaner 36 (FIG. 1).It is also contemplated that the after-air could be preheated in anysuitable manner by, for example, passing the after-air through a heatexchanger to exchange heat with exhaust gases of the internal combustionengine.

The liquid additive and after-air induction system also includes aliquid additive supply line 141 leading into the conduit 200, and avalve (or valving arrangement) 142 for controlling flow into the liquidadditive supply line 141, a water supply line 145 leading from a watersupply reservoir 143 to the valve 142, and an alcohol supply line 146leading from an alcohol supply reservoir 144 to the valve 142. The valve142 can be any suitable valve which can control the flow of the waterand alcohol in the situation where both water and alcohol are used, or,in a situation where only one of the water or alcohol is used, can be acontrol valve which simply controls flow of a single line. It is alsocontemplated that the alcohol supply in the supply reservoir 144 couldbe replaced by some other additive, such as benzene, or that a furthersupply reservoir could be added. Each of the reservoirs 143 and 144 isunder atmospheric pressure due to the respective vents 147 and 148. Thecontrol valve 142 is controlled by an after-air and/or liquid additiveinduction control 131.

FIG. 20 shows a first example of the after-air and/or liquid additiveinduction control 131. In this arrangement, a manual control knob 131ais provided to allow for manual control of the after-air control valve26a and the liquid additive control valve 142. Although an electroniccontrol scheme can be used in this regard to electronically couple themanual control knob 131a to the valves 26a and 142, a physicalinterconnection by way of a wire and/or linkage connection iscontemplated. This manual version of the after-air and/or liquidadditive induction control 131 is contemplated for use by race cardrivers, truck drivers or other individuals who would have the necessarydesire and experience to control an internal combustion engine in thismanner.

However, for passenger automobiles, it is contemplated that an automaticafter-air and/or liquid additive induction control 131 would be used.Such automatic control 131b is shown in FIG. 21. This automatic controlcould utilize a separate computer 134 or the main computer of today'spassenger automobiles. Various sensors, such as a tachometer (or otherspeed sensing means) 135, a temperature sensor 136 and a fuel-airmixture sensor 137, will provide sensing input into the computer 134 toallow the computer 134 to control the valves 26a and 142 in a suitablemanner. The ordinary artisan will understand the manner of controllingthe valves 26a and 142 on the basis of the sensor inputs from thesensors 135, 136 and 137 to input the proper amounts of after-air andliquid additives. This can be determined by minor amounts ofexperimentation. Therefore the computer 134 can be properly programmedto suitably control the valves 26a and 142 on the basis of the sensorinputs. Fuel-air mixture sensors are themselves well known and areavailable from various companies, including Fuel Management Systems ofMundelien, Ill.; Automotive Controls Corporation of Brantford, Conn.;and B.D E. Limited of Minnesota.

With regard to the control of the after-air control valve 26a, thesignificantly improved efficiency of the combustion of the fuel-airmixture when the fuel-air bypass of the present invention is providedenables the fuel-air mixture to be much leaner and, accordingly, aquantity of after-air can be quite significant. Although the exactquantity of after-air must be determined experimentally for eachparticular engine and each particular configuration of the fuel-airbypass device, it can generally be expected that the after-airvolumetric capacity can be 50% to 100% of the volumetric throttlecapacity.

The purpose of the water and/or alcohol induction into the fuel-air flowin the conduit 200 is to allow for the use of a higher compressionengine than would otherwise be possible with unleaded gasolines, and tootherwise improve the engine performance and efficiency. In particular,the water induced into the fuel-air mixture will slow the burning of themixture, and therefore slow the advance of the flame front, to therebyprevent knocking in the same manner that was previously accomplished bythe provision of tetryl ethyl lead in gasoline. Although water inductionhas been previously attempted, it has never been successful forlong-term running of an internal combustion engine because the watercould never be properly atomized and mixed with the fuel-air mixture inprior art close-coupled systems (i.e., systems in which the fuel-airmixing device 11 is coupled directly to the intake manifold 12). Thelength, cross-sectional area, heat conduction capacity, and turbulencecreating capacity of the fuel-air bypass conduit device of the presentinvention enables the water induced into the conduit 200 to be veryfinely atomized and properly mixed in the fuel-air mixture so that amixture is readily combusted in the cylinders. In addition to slowingthe burning of the fuel-air mixture, the water added thereto iseffective to itself perform work in the cylinder due to the fact thatwater expands approximately 19,000 times when it flashes into steam. Thewater also will interact with carbon, and thus has a purging effect inthe combustion chamber to prevent carbon build-up.

Because it is highly undesirable to have any water present in thecylinders when the engine is not running, it is contemplated in thepresent invention that the control valve 142 will be controlled so thateither less water or no water will be induced into the conduit 200during idling. Rather, during idling, the water induced into the conduit200 will be replaced by alcohol from the alcohol reservoir 144. Thealcohol has a similar effect to the water in that it also preventsknocking in a high compression engine by slowing burning of the fuel-airmixture. However, it is desired to use water rather than alcohol as theadditive when possible, because alcohol is much more costly an additiveand also cannot be as readily replenished.

FIG. 22 shows a system for providing an initial fuel injection burstinto the conduit 200, preferably at a location in the conduit near theinlet to the intake manifold 12. This initial injection of fuel allowsfor a quicker turn-over of the engine, which is otherwise slowed due tothe large capacity of the conduit 200. Although various systems for soproviding this initial fuel injection burst may be contemplated, apreferred embodiment of the present invention includes a fuel injector150 mounted to the conduit 200 and injecting directly thereinto, atemperature sensor (which is preferably an on/off switch-type sensor)152 and a fuel injector supply line 153. The fuel injector supply line153 branches off from a fuel line 38 leading from a fuel pump 37 to thefuel-air mixing device 11. The fuel pump 37 is supplied by a fuelreservoir 39 via a fuel supply line 40. The automobile ignition switch151 is connected to the on/off temperature sensor 152 which, in turn, isconnected to the fuel injector 150. When the ignition switch 151 isturned on, and the temperature sensor 152 is also switched "on", thefuel injector 150 will be electrically actuated. The temperature sensor152 is placed in an "on" condition when it senses a temperature in theconduit 200 below a reference temperature. The reference temperature isa temperature above which an initial fuel injection burst is unnecessaryto cause quick starting of the engine. This fuel injection system isused especially when there is no acceleration pump.

FIG. 23 shows a reparticulation reservoir, one or more of which arepreferably located at the physically lowest portion of the bypassconduit to collect any liquid fuel therein in the case of flooding ofthe engine. The reservoirs collect the excess liquid fuel caused byflooding and reduce the surface area of the liquid to the air flow. Thisprovides for a more gradual re-absorption of this liquid into thefuel-air flow than would be the case where the liquid fuel is layingacross a large surface area, such as pooled in the bottom of an intakemanifold. In the preferred embodiment shown in FIG. 23, thereparticulation reservoir is formed by an externally threadedreparticulation fitting 161 to which an internally threadedreparticulation nut 162 is secured. This removable reservoir arrangementallows for a drastically flooded situation to be remedied by removal ofthe reparticulation nut 162 to drain the excess liquid fuel. However, itis also contemplated that the reparticulation reservoir 160 can be inthe form of a simple dimple or other outward deformation in the bottomof the conduit 200, or in any other suitable form to carry out theabove-discussed function. One or more of the reparticulation reservoirs160 can be provided in the bypass conduit 200. In addition, in a bypassconduit 200 formed of multiple conduit sections, a separatereparticulation section 200j can be utilized.

The fuel-air bypass device of the present invention can be mounted in anengine compartment or other enclosed environment in any suitable manner,so long as it is interposed between the fuel-air mixing device and theintake manifold of an internal combustion engine. The engine can be aliquid-cooled engine or an air-cooled engine, and also can be a singlecylinder engine such as a lawnmower engine, or a multiple cylinderengine such as used in automobiles. However, it must be recognized thatthe elongated fuel-air bypass conduit 100 or 200 must be exposed toconsiderable heat and it is generally contemplated that the heat will bethe heat produced by the internal combustion engine itself. It has beenfound that the heat produced in the engine compartment of an automobileis more than sufficient to enable the bypass conduit device of thepresent invention to sufficiently heat the fuel-air mixture prior to itsentry into the cylinders so that the fuel of the mixture is gasifiedbefore entering the cylinders and, preferably, before entering theintake manifold.

The precise configuration of the bypass conduit can be varied asnecessary for the particular engine arrangement and/or the particularengine compartment arrangement. Examples of three exemplary bypassconduit configurations 200A, 200B and 200C are depicted in plan view inFIGS. 29A, 29B and 29C, respectively.

In addition, the bypass conduit can have any suitable cross-sectionalshape such as, for example, a circular cross-sectional shape as depictedin FIG. 27, or a square or rectangular cross-sectional shape as depictedin FIG. 28. It is contemplated that the turbulence creating means of thebypass device can be in the form of helical-like inward deformations201. These deformations 201 can be provided about the entire peripheryof a cross-section of the conduit, but, in the coil-like configurationof the conduit 200E in FIG. 27, it is possible to provide thedeformations 201 only along the outer circumference of the coil-shapedconduit, and such arrangement will sufficiently mix the fuel-air mixturedue to the centrifugal force of the fuel-air mixture flowing through thecoil-shaped conduit.

As shown in FIG. 28, it is contemplated that rectangular-shaped inwarddeformations 202 can be provided in the outer periphery of a coil-shapedconduit 200F, and that such rectangular-shaped deformations will alsoprovide an adequate turbulence creating means.

FIG. 26 shows a fuel-air bypass conduit 200D mounted in the enginecompartment 220 of an automobile. In this particular example, theconduit 200D is mounted to the inside wall of a fender 225, and has itsoutlet end connected to the intake manifold 222 of the engine 221 via aflexible conduit 223. The inlet of the conduit 200D is, of course,connected to the fuel-air mixing device 224. This exemplary mountingconfiguration shown in FIG. 26 is only one of many configurationspossible.

It is preferred that the mounting of the conduit to the engine or enginecompartment walls will be somewhat flexible so as to allow for anythermal expansion and contraction of the conduit. FIGS. 24 and 25 showtwo examples of how the conduit 200 can be mounted to the engine orengine compartment wall. In particular, a conduit mounting tab 210 canbe either welded to the conduit 200 (as shown in FIG. 24), or attachedto the conduit 200 by adjustable conduit mounting clamps 212 (as shownin FIG. 25). A conduit mount 211 which is secured in any suitable mannerto the engine or engine compartment wall can then be pivotally attachedto the conduit mounting tab 210 by a bolt or other suitable pivot pin.

Actual tested examples of the present invention will now be described.

EXAMPLE 1

A 11/2 inch O.D. tubular steel conduit was interposed between thecarburetor and intake manifold of a 350 cubic inch engine in a 1968Buick. As with all of the present examples, the conduit was a type Lconduit having a wall thickness of approximately 1/16 inch. Theturbulence creating means utilized in this and the following examplescomprised venturis spaced along the conduit. This bypass device wastested with conduits of five different lengths: 3 feet, 6 feet, 9 feet,12 feet, and 20 feet. With each of these arrangements, the vehicle wasable to perform at a full range of conditions and speeds up to almost100 miles per hour, and the throttle response was almost instantaneousfor all of the five configurations. However, the steel conduit, attimes, demonstrated considerable sweating at cold start-up due to therefrigerant effect. That is, when the fuel was introduced into the airstream, it took heat from the steel conduit faster than the steel couldabsorb heat and transfer it to the fuel-air stream. This condition ofslow conduction by the steel conduit causes freeze-up in cold wintertemperatures, and ice or frost build-up on the inside of the conduitwill choke off the air supply to the engine. Also, frost build-up on theoutside of the conduit will prevent any appreciable heat absorption fromtaking place.

EXAMPLE 2

In a 1977 Buick with a 403 cubic inch engine, a 11/2 inch O.D. bypassconduit was interposed between the carburetor and the intake manifold.The configuration of the conduit was somewhat like that shown in presentFIG. 29B. This time, rather than a steel conduit, the conduit wascopper, and had a length of 12 feet. With this arrangement of thefuel-air bypass device, it was found that no sweating occurred, therebydemonstrating the superiority of copper conduit over steel. However, the11/2 inch O.D. copper conduit proved unable to supply a sufficientvolumetric amount of the fuel-air mixture to meet the engine's powerneeds, thereby causing a significant drop in performance relative to thenon-retrofitted engine and a drop in average fuel economy toapproximately 9 miles per gallon with a top speed of approximately 45miles per hour.

EXAMPLE 3

This example of the fuel-air bypass device was substantially identicalto that of Example 2, except that a 2 inch O.D. copper conduit was usedwhich, having a 12 foot length, provided the conduit with over 6 squarefeet of heating surface area. In this arrangement, normal power wasrestored to the engine relative to Example 2, and the engine performedover a full range of speeds and conditions.

The success of this test, compared with that of the test in Example 2,showed that the flow capacity and resulting resistance characteristic ofthe conduit directly affect the power that can be developed and the fuelmileage.

Further testing of this example demonstrated that the acceleration pumpnormally used with automobile engines was no longer needed. Normalacceleration was achieved without the acceleration pump (i.e., bycontrolling only the carburetor throttle), and there was found to be nohesitation in the acceleration.

In this example, the fuel mileage attained increased from an average of15 to 16 miles per gallon with the non-retrofitted engine to an averageof 22 to 24 miles per gallon with the fuel-air bypass device of thepresent invention.

The exhaust emissions were tested for this arrangement and showed, at anidle speed of 450 rpms, a hydrocarbon output of 26 ppm and a carbonmonoxide output of only 0.02%. At an engine speed of 2000 rpms, thehydrocarbon output was 10 ppm and the carbon monoxide output was 0.01%.

EXAMPLE 4

In a 1982 Toyota Corona 4-cylinder engine, a fuel-air bypass devicehaving a 11/2 inch O.D. copper conduit with a length of 12 feet wasinstalled. The configuration of the conduit was somewhat like that shownin FIG. 29C. This arrangement also performed well over a full range ofspeeds and conditions. The average fuel mileage with the fuel-air bypassdevice installed was 36 to 38 miles per gallon, whereas the originalfactory estimate miles per gallon for this engine was 25 miles pergallon.

EXAMPLE 5

In a 1984 Chevrolet pickup with a 350 cubic inch engine, a fuel-airbypass device having a 2 inch O.D. copper conduit with a length of 12feet was installed. In addition, the device used in this example wasprovided with water induction. Again, the engine ran without problemsover a full range of engine speeds and conditions. Also, the exhaustemissions were tested to show that the hydrocarbon output was 9 ppm, andthe carbon monoxide output was only 0.03% at an engine speed of 2521rpms. This arrangement was also found to run and accelerate properlywithout an acceleration pump.

EXAMPLE 6

In a Briggs and Stratton 5 horsepower air-cooled lawnmower engine (Model30202), a fuel-air bypass device having a 3/4 inch O.D. copper conduitwith a length of 3 feet was installed. The configuration was similar tothat shown in FIG. 29C. The engine ran well over a normal range ofengine speeds and, when initially installed, the engine speed increasedby over 100%.

Although various embodiments of the invention and of various features ofthe invention have been described in detail, the above descriptionshould be understood as being only exemplary of the invention.Therefore, it will be understood that various modifications of theconstruction and operation of the above-described embodiments will beapparent to those of ordinary skill in the art. Accordingly, the scopeof the present invention is to be limited only by the appended claims.

We claim:
 1. An apparatus for use with an internal combustion engineincluding a fuel-air mixing device with an inlet port and an outletport, an intake manifold with an inlet port operably communicated withthe outlet port of the fuel-air mixing device and at least one outletport, and at least one cylinder communicated with the at least oneoutlet port of the intake manifold, said apparatus comprising:anelongated bypass conduit operably coupled between the outlet port of thefuel-air mixing device and the inlet port of the intake manifold forpassing a fuel-air mixture from the fuel-air mixing device to the intakemanifold; turbulence creating means for creating turbulence in thefuel-air mixture flowing through said elongated bypass conduit; whereinsaid elongated bypass conduit is formed of a thermally conductivematerial; and wherein said elongated bypass conduit has a length, anexterior surface area and a thermal conductivity sufficiently great soas to constitute a means for causing liquid fuel introduced through thefuel-air mixing device to change from a liquid state to a gaseous stateprior to entry into the at least one cylinder without requiring saidelongated bypass conduit to be connected to a heat exchanger.
 2. Anapparatus as recited in claim 1, wherein said elongated bypass conduitis formed of copper.
 3. An apparatus as recited in claim 1, whereinsaidturbulence creating means comprises a plurality of baffles provided insaid elongated bypass conduit successively along the length thereof. 4.An apparatus as recited in claim 3, wherein said baffles protrudeinwardly from a conduit wall of said elongated bypass conduit.
 5. Anapparatus as recited in claim 3, whereinsaid baffles comprise helicalplates respectively mounted along the length of said elongated bypassconduit.
 6. An apparatus as recited in claim 1, whereinsaid elongatedbypass conduit is circular in cross section.
 7. An apparatus as recitedin claim 1, whereinsaid elongated bypass conduit is rectangular in crosssection.
 8. An apparatus as recited in claim 1, whereinsaid fuel-airbypass conduit is formed of a plurality of conduit sectionslongitudinally successively secured together.
 9. An apparatus as recitedin claim 1, further comprisinga compartment for enclosing said elongatedbypass conduit and the internal combustion engine.
 10. An apparatus asrecited in claim 9, further comprisinga heat exchanger operably coupledto said elongated bypass conduit and operably couplable to a heatsource.
 11. An apparatus as recited in claim 1, further comprisinga heatexchanger operably coupled to said elongated bypass conduit and operablycouplable to a heat source.
 12. An apparatus for use with an internalcombustion engine including a fuel-air mixing device with an inlet portand an outlet port, an intake manifold with an inlet port operablycommunicated with the outlet port of the fuel-air mixing device and atleast one outlet port, and at least one cylinder communicated with theat least one outlet port of the intake manifold, said apparatuscomprising:an elongated bypass conduit operably coupled between theoutlet port of the fuel-air mixing device and the inlet port of theintake manifold for passing a fuel-air mixture from the fuel-air mixingdevice to the intake manifold; turbulence creating means for creatingturbulence in the fuel-air mixture flowing through said elongated bypassconduit; wherein said elongated bypass conduit has a length, an exteriorsurface area and a thermal conductivity sufficiently great so as toconstitute a means for causing liquid fuel introduced through thefuel-air mixing device to change from a liquid state to a gaseous stateprior to entry into the at least one cylinder; and wherein saidelongated bypass conduit is formed of copper.
 13. An apparatus for usewith an internal combustion engine including a fuel-air mixing devicewith an inlet port and an outlet port, an intake manifold with an inletport operably communicated with the outlet port of the fuel-air mixingdevice and at least one outlet port, and at least one cylindercommunicated with the at least one outlet port of the intake manifold,said apparatus comprising:an elongated bypass conduit operably coupledbetween the outlet port of the fuel-air mixing device and the inlet portof the intake manifold for passing a fuel-air mixture from the fuel-airmixing device to the intake manifold; turbulence creating means forcreating turbulence in the fuel-air mixture flowing through saidelongated bypass conduit; wherein said elongated bypass conduit isformed of a thermally conductive material; wherein said elongated bypassconduit has a length, an exterior surface area and a thermalconductivity sufficiently great so as to constitute a means for causingliquid fuel introduced through the fuel-air mixing device to change froma liquid state to a gaseous state prior to entry into the at least onecylinder; and wherein said elongated bypass conduit comprises a conduitwall, and a plurality of longitudinally spaced apart portions of saidconduit wall are deformed inwardly toward an axial center of saidconduit wall, said inwardly deformed portions of said conduit wallconstituting said turbulence creating means.
 14. An apparatus for usewith an internal combustion engine including a fuel-air mixing devicewith an inlet port and an outlet port, an intake manifold with an inletport operably communicated with the outlet port of the fuel-air mixingdevice and at least one outlet port, and at least one cylindercommunicated with the at least one outlet port of the intake manifold,said apparatus comprising:an elongated bypass conduit operably coupledbetween the outlet port of the fuel-air mixing device and the inlet portof the intake manifold for passing a fuel-air mixture from the fuel-airmixing device to the intake manifold; turbulence creating means forcreating turbulence in the fuel-air mixture flowing through saidelongated bypass conduit; wherein said elongated bypass conduit isformed of a thermally conductive material; and wherein said elongatedbypass conduit comprises a conduit wall, and at least onereparticulation reservoir is provided in a bottom portion of saidelongated bypass conduit, said at least one reparticulation reservoircomprising a liquid-collection container fluidically communicated withan interior of said elongated bypass conduit and projecting downwardlyfrom said conduit wall in a direction away from said elongated bypassconduit.
 15. An apparatus as recited in claim 14, whereinsaidliquid-collection container projects downwardly from a physically lowestpoint of said elongated bypass conduit.
 16. An apparatus as recited inclaim 14, wherein said elongated bypass conduit has a length, anexterior surface area and a thermal conductivity sufficiently great soas to constitute a means for causing liquid fuel introduced through thefuel-air mixing device to change from a liquid state to a gaseous stateprior to entry into the at least one cylinder.
 17. A method comprisingthe steps of:mixing fuel and air to create a fuel-air mixture; feedingthe fuel-air mixture to at least one combustion cylinder of an internalcombustion engine; prior to entry of the fuel-air mixture into the atleast one combustion cylinder, gasifying the fuel of the fuel-airmixture by causing the fuel-air mixture to pass through an elongatedbypass conduit which is formed of a thermally conductive material and isheated by heat from the internal combustion engine; creating turbulenceof the fuel-air mixture in the elongated bypass conduit; and supplyingalcohol into the elongated bypass conduit to be mixed with the fuel-airmixture prior to entry of the fuel-air mixture into the at least onecylinder.
 18. A method comprising the steps of:mixing fuel and air tocreate a fuel-air mixture; feeding the fuel-air mixture to at least onecombustion cylinder of an internal combustion engine; prior to entry ofthe fuel-air mixture into the at least one combustion cylinder,gasifying the fuel of the fuel-air mixture by causing the fuel-airmixture to pass through an elongated bypass conduit which is formed of athermally conductive material and is heated by heat from the internalcombustion engine; creating turbulence of the fuel-air mixture in theelongated bypass conduit; and supplying water and alcohol into theelongated bypass conduit to be mixed with the fuel-air mixture prior toentry of the fuel-air mixture into the at least one cylinder.